#ac-wrapper { 
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('images/pop-bg.png') left top;
    z-index: 1001;
}
#popup {
    background: none repeat scroll 0 0 #FFFFFF;
    border-radius: 18px;
    -moz-border-radius: 18px;
    -webkit-border-radius: 18px;
    height: 942px;
    margin: 10% auto;
    position: relative;
    width: 750px;
}